Detect Power Failure

[koossa]

Hi Picers

What would be the easiest way to detect a power failure using a PIC?

Thank you

Koossa

[mister_e]

You'll need to be more precise in your need. What kind of power failure?

If you want to monitor the PIC itself, you may look some STATUS register bits.

[koossa]

I've got 2 remote PCs, one that runs on a power backup and one that's connected directly to the electricity.
I just want to be notified when there is a power failure, so the pic needs to be connected to the "power backup pc" and when the power drop, it must send something to the PC via RS232 and the PC must send me an SMS or email.
I will run the PIC from battery, but how do I easily detect when the power drops?

Thank you!

[BobP]

Hi,

I would detect the 5v from the PC's USB socket. When 5v disappears check again for about 400mS to allow for spikes then send your serial data to the other PC.

Bob

[koossa]

Great!
I would try it!

[koossa]

Will I use a Transistor to detect power on the USB Port?